Exhaust system



United States Patent G 3,1725% EXHAUST SYSTEM Ervin C. Lentz, Jackson, Mich, and William G. McKenzie, Racine, Wis., assignors to Walker Manufacturing Company, a corporation of Delaware Filed Dec. 13, 1961, Ser. No. 159,124 13 Ciaims. (Cl. 123-119) This invention relates to internal combustion engine crankcase ventilating systems and more particularly to an engine crankcase ventilating system wherein crankcase vapors and gases are withdrawn from the crankcase and delivered to the engine carburetion device for delivery to the engine combustion chambers.

The vapors and gases which accumulate in the crankcase during internal combustion engine operation are commonly referred to as blowby. In general, two types of crankcase ventilating systems have been previously proposed. In one type of system blowby is exhausted directly to the atmosphere. Such a system is commonly provided by a road draft tube which extends downwardly from the crankcase and atmospheric air inlet means connected to the crankcase at some other point to establish a flow of air which will carry blowby out the road draft tube. The discharge of blowby to the atmosphere is undesirable because of the contaminating effect thereof. In the other type of system, the contamination of the atmosphere by blowby is eliminated by discharging the blowby into the engine intake manifold, the air intake passage means, or some other portion of the combustion air delivery system. In such systems, the blowby is returned to the combustion chambers and consumed rather than being dumped to the atmosphere. This invention relates particularly to a crankcase ventilating system wherein the blowby is returned to the combustion chambers rather than being discharged to the atmosphere.

It is an object of this invention to provide a venttilating system which is relatively simple in construction and de sign, and therefore can be economically manufactured and easily installed.

Another object of the present invention is to provide a crankcase ventilating system which is easily installed by association with conventional internal combustion engine components. In this regard, it is a further object of the present invention to provide crankcase ventilating means which are equally Well adapted for use on existing vehicles currently in use and for new vehicles to be hereafter designed and manufactured.

A further object of the present invention is to provide crankcase ventilating apparatus for delivering blowby from an engine crankcase to the engine air induction system without oil droplets from the crankcase and without undesirable accumulation of condensate in the apparatus. To this end, it is an object of the present invention to provide oil removal means to cause oil entrained in the blowby to be returned to the crankcase and to provide condensate trap means to condense, remove, and collect moisture in the blowby.

Still a further object is to provide, as a part of the ventilaing system, a new and improved crankcase oil filler tube breathing unit through which a controlled flow of air from the atmosphere to the crankcase may be established for ventilation purposes. In this regard, it is an object of the present invention to provide oil filler tube breathing means which is readily adaptable for use with a variety of filler tube designs.

Still another object of the present invention is to provide an oil filler tube cap construction having new and improved air filtering means and to provide control valve means for incorporation in an ventilating system in the air inlet passage to the crankcase.

e artisan EQQ Patented Mar. 9, 1965 Another object of the present invention is to provide a new and improved condensate collecting means in association with a ventilating system to provide a positive way to remove condensation from the system in a controlled manner. In this respect, it is a further object or" the present invention to provide a combination condensate collecting device and fire trap to prevent a backfire condition in the engine air induction passage means from reaching the crankcase.

Another object of the present invention is toprovide an improved ventilation system conduit arrangeemnt and conduit fastening means for associating the ventilating system conduits with the engine components in a simple and inexpensive manner whereby the system is readily connectable in various ways and at varying locations to the engine crankcase and engine components.

Other objects and advantages of the present invention will be apparent or become apparent by reference to the following detailed description and the accompanying drawing wherein:

FIGURE 1 is an end elevational view, partly in section, of a conventional internal combustion engine and accessory components thereof incorporating a crankcase ventilating system in accordance with the principles of the invention;

FIGURE 2 is a partial side elevational view taken along the line 2-2 in FIGURE 1 showing a portion of the ventilating system;

FIGURE 3 is a sectional view taken along the line 33 in FIGURE 2;

' FIGURE 4 is a top view of a portion of the ventilating system shown in FIGURE 1 taken in the direction of the arrow 4-4;

FIGURE 5 is a sectional view taken along the line 55 in FIGURE 4;

FIGURE 6 is a sectional view taken along the line 6-6 in FIGURE 5;

FIGURE 7 is a top view of an alternative embodiment of the apparatus shown in FIGURES 46; and

FIGURE 8 is a sectional view taken along the line 8-8 in FIGURE 7.

Referring now to FIGURE 1, a conventional internal combustion engine It) comprising a crankcase 12 and an oil filler tube 14 is illustrated. The filler tube 14 is connected to the engine oil in the crankcase and a filler tube cap 16 is conventionally mounted on the end thereof in any of a variety of ways. The engine is further provided with conventional accessory components in the form of an intake manifold 18, carburetion means 20, and an air cleaner unit 22. The carburetion means 20 includes a combustion air induction passage 24 and a throttle valve 26. The air cleaner unit 22 includes an annular housing 28 which supports an annular filter unit 30. A cover 32, which is fastened to the housing 28 by conventional fastening means 34, secures the filter unit on the housing. A tuning chamber 36 is provided by the housing 28 and communicates with the air induction passage 24 through an annular opening 37 spaced circumjacent thereto. The air cleaner illustrated is open to the atmosphere through 360 around the entire periphery of the annular filter unit 30. Air is drawn radially inwardly through the filter unit and downwardly through a central passage 38 into the air induction passage 24.

The aforedescribed engine and engine components are intended to be merely illustrative in many respects. It should therefore be particularly understood that the air cleaner unit described and the carburetion means shown may, in the broadest aspects of the present invention, take the form of any of the variety of designs currently in use. Although a 360 air cleaner having a tuning chamber has been described and produces a particular result in combination with the subject ventilating system, an air Ii cleaner of any design with or without a tuning chamber may also be adapted for use with the ventilation system of the present invention as hereinafter described.

The present invention is directed to a ventilation 'sys-.

tern whichmay take the form of an adapter kit having ventilating system components which may be readily associatedwith conventional internal combustion engine components to provide forcrankcase ventilation on those vehicles which are used in areas requiring crankcase ventilation. Accordingly, the present ventilation system may be easily installed on existing internal combustion engines currently in use and is readily adaptable for varying vehicle makes and varying engine designs thereof. The ventilating system is, of course, equally well suited for factory installation on new cars if desired. In general, the ventilation system components comprise a novel breather cap 16, which may include flow control means and which is adapted to be substituted for a conventional oil filler tube cap on old cars now in use, lengths of flexible hose t), 52, an adapter tube 54-, and a combination condensate and fire trap 56.

The flexible hose are provided with a plurality of external convolutions 58 which define V-shaped grooves 59 and are made from a material such as thick neoprene rubber which will withstand exposure to varying conditions of engine operation and-to oil, gasoline, and blowby contamination. In the broadest aspects of the invention, the illustrated hose design is not critical except insofar as the hose material need be sufiiciently flexible forinstallation and resistant to chemical reaction and deterioration. However, particularly advantageous results are obtained by the illustrated preferred hose construction in regard to the means of connecting the hose to the engine components as hereinafter described.

The length of hose 52 is adapted to be connected at one end to the adapter tube 54. The adapter tube 54 may take any of a plurality of forms and maybe designed to be secured within or to an existing engine passage which communicates with the crankcase or to be inserted through a specially prepared opening in the crankcase Wall. The end of the adapter tube extending outwardly from the engine is designed with an outside diameter which snugly receives the hose 52 in telescopic relationship. A conventional wire clamp 60 maybe provided to secure the hose on the adapter tube. Oil separating means in the form of an oil removing deflector plate 62 having a plu- I rality of small apertures is centrally mounted. within the hose 52. The deflector has a zig-zag configuration and is slightly oversize relative to the inside diameter of the hose for retention thereby. The deflector 62 is adapted to remove oil entrained in the blowby as it flows through the hose. The deflector is preferably located at a bend in the hose. The. bend is located at the highest position of the hose and is vertically positioned above the adapter tube 54 so that oil removed by the deflector will return to the crankcase. The section of the hose on the other side of the deflector is inclined downwardly and connected at its lower end to the combination condensate and fire trap 56.

As shown in FIGURES 2 and 3, the trap 56 comprises a pair of mating shells 70, 72 which are secured to one another by overlapped flanges 74, 76 to define a chamber 78. The chamber 78 has a bottle-shaped cross-sectional configuration including a lower portion of substantially constant cross-section and an upper portion of varying cross-section defined by inwardly tapering wall portions 80, 82. Connecting holes. 84, 86 are provided fastening means and seal between the end of the hose and the circurnjacent wall of the trap. A baflie plate 96 is provided between the openings 84, 86 to prevent direct passage of blowby from one opening to the other. The chamber 78 is filled with a copper mesh pad 1% beneath the baflie 9s. The pad serves as a fire trap to prevent any flames or sparks from passing through the chamber 78 between the openings 84, 86. At the bottom of the trap an outlet opening 102 is formed in a side wall. A rubber flap valve 194 is secured to the trap by a projecting portion 1% which is received within a corresponding opening 108 provided in the trap wall above the opening 102.. The lower end of the valve overlies the opening 102 to permit condensate collected in the chamber 78 to drain outwardly but prevent the passage of air inwardly.

The length of hose 50 is mounted in the hole 86 in a manner similar to that previously described for mounting the length of hose 52 in the hole 84. The hose 50 extends upwardly and is connected at its other end to the induction air passage means at some convenient point. The most convenient point is through a side wall of the air cleaner. In the illustrative air cleaner structure, the end of the hose is shown to be connected to the tuning chamber 36 through a hole 110 in the bottom Wall .of the cleaner housing. The hose may be connected in the hole 110 in a manner identical to that previously described in relation to the hose length 52 and the hole 84 in the fire trap. The hole 110 may be formed in the cleaner housing 28 at the time of installation of the ventilating system in any conventional manner such as by a cuttin or piercing operation. The particular location of the hole 110 is not critical and the flexible hose 5% could 'also be connected in a side wall at 112 or through the cover at 114. However, particularly advantageous results are obtained in so far as the collection of condensate is concerned by bringing the hose into the lowermost portion of the air cleaner so that condensate will readily dr-ain back to the trap. With the hose connected to a bottom wall of the air cleaner condensate collecting in the tuning chamber will drain downwardly through the hose 50 and into the trap 70. In addition condensate which collects on the walls of the hose 50 and the upwardly extending portion of the hose 52 will also drain into the trap. When the condensate in the trap reaches the level of the opening 102 the condensate will drain outwardly through the flap valve 104.

In order to establish a ventilating flow of air through the crankcase, a special filler tube cap 15 is provided for association with the tiller tube 14 as part of the ventilating system. Referring now to FIGURES 4-6, the preferred form of filler cap comprises a cover portion 13d, a filler tube receiving bushing 132, filter means 134, air, inlet passages 136, and flow control means inthe form of a valve element 138 providing a flow of ventilating air at a rate determined. by the flow resistance of the filter means 134, air inlet passages 136, etc. The cover portion 136 has a cylindrical side wall 140 and a generallycurvilinear top wall 142. The top wall is provided with a plurality of radially extending depressions 144, 146, 148, as shown in FIGURE 4, which terminate in a centrally depressed wall portion 150. The depressions 144, 146, 14 8. are inwardly stepped by the provision of transversely bent axially extending side wall portions 152, 154, 156 which are connected by curved transversely bent axially extending side wall portions 158, 169, 1e2. The bottom walls of the depressions 144, 146, 148 form abutment surfaces 166, as shown in FIGURE 5, for the valve mem her 138 and limit its upward movement.

A valve support element 1'70 having a pair of radiallyspaced cylindrical walls 172, 174 connected by a transversely extending web portion 176 is mounted within the cover 130. The walls 172, 174 are dimensioned to abuttingly engage theinner surface of the wall 14% of the: cover and the outer surface of side Wall portions 152,v 154, 156. A pair of radially spaced emhossments or ribs 178, 180 are provided in the web portion and extend outwardly upwardly therefrom in a direction opposite to the side walls 172, 17 i. A plurality of air inlet passages 136 are provided around the central web portion between the ribs 173, 18% as shown in FIGURE 6.

The inlet bushing 132 is adapted to be telescopically mounted relative to the inner wall 172 of the valve support member 176 and secured thereto by any conventional means such as welding. The inlet bushing 132 is further provided with a centrally located annular shoulder 180 which is adapted to abut the end of the filler tube 14 and locate the cap thereon. In order to secure the cap on the filler tube 14 fastening means in the form of a plate spring retainer 182 is secured to the bottom wall 150 by a rivet or the like. The particular design of the inlet bushing 180 and the spring means 182 may be varied as desired to accommodate varying types of filler tube structure. For exam e, some filler tube caps are conventionally provided with bayonet type locking means. In order to accommodate a bayonet type lock or other means, the'inlet bushing structure 132 may be changed to provide a corresponding lock portion without changing the basic cap structure. Thus, for engines embodying alternative filler cap structure, the inlet bushing and fastening means can be varied so that an adapter kit for a particular make and model of an automobile would have suitable fastening means incorporated in the filler cap structure.

The inlet bushing and valve support element 170 are mounted within the cover 130 and may be secured therein by a plurality of radially inwardly bent tabs 186 which are integrally for-med in the lower end of the side wall of the cover. The valve element 138 comprises an annular plate which is supported in a valve cavity defined by the outer side wall 140 of the cover, the inner side walls 152, 15 i, 156, the bottom walls 166 of the depressions 144, 146, 14-8, and the central web 176 of the valve support element on the annular ribs 178, 186. In this manner the valve element is movable upwardly off of the ribs 178, 189 to permit atmospheric air to flow in through the inlet ports 136 and into the filler tube 14. Communication between the cover 134 and the filler tube 14- is provided by a plurality of passages 190, 192, 194 formed by the inner side walls 158, 160, 162 of the cover 130, and the inner side wall 172 of the valve support element 179. An annular filter element .134 of polyurethane foam or the like may be pressed into the cavity between the side walls 172, 174 to filter all incoming air. The valve provides one way flow of filtered air from the atmosphere to the crankcase through the filler tube and prevents any reverse flow of blowby from the crankcase to the atmosphere.

An alternative embodiment of the filler cap is shown in FIGURES 7 and 8. The structure comprises a cover 260 having a cylindrical side wall 202 and a curvilinear central wall 204-. An annular valve support element 206 having radially spaced cylindrical walls 208, 21% which are connected by a central web portion 212 is welded or otherwise secured to an inlet bushing 214. The valve support element 286 is provided with radially spaced upwardly extending ribs 216, 218, and a plurality of inlet passages 220 as hereinbefore described. The upper end of the inlet bushing is provided with a radially outwardly extending flange 222 to provide an abutment surface for an annular valve 224. Tab elements 226, 228 are inwardly bent from the central portion of the inlet bushing to provide locating stops for the filler tube 14 which is adapted to be telescopically received therewithin. Spring means 23% may be secured to the cover by a rivet 232 or the like to resiliently engage the inner surface of the filler tube and secure the breather cap thereon. In order to limit upward movement of the valve 224 a plurality of inwardly extending nibs 234, 236, 238 are provided in the cover. The nibs are adapted to engage and space the valve from the upper wall of the cover in the uppermost position of the valve. As hereinbetore described, a filtering element 239 of polyurethane or the like is frictionally inserted between the side walls 268, 210 of the support element 2%. The entire unit is secured within the cover by a plurality of radially inwardly extending locking tabs 240 and such other fastening means as may be necessary. The operation of the device is identical to that described in relation to the alternative filler cap struc ture.

in adaptation of the subject filtering system to conventional engine structures, the conventional filler cap is replaced by a filler cap incorporating a filtering element and valve means as hereinbefore described. A suitable adapter tube 54 is connected to the engine through a passage in communication with the engine crankcase. An inlet opening of appropriate size is formed in a side wall of the air cleaner means. The length of hose 52 is secured to the adapter tube at one end and the central portion of the conduit containing the deflector 6-2 is fixedly located at a point spaced thereabove. The fire and condensate trap 56 is fixedly mounted in any suitable manner below the defiector 62 and below the air cleaner. The end of the hose 52 is connected to the trap by compression and insertion through the opening 84. The other hose element 5d is connected in a similar manner to the opening 8:5 in the trap 56 at one end and to the air induction means through the opening 119 formed therein at the other end.

Pressure diiterentials existing between the air induction means in the crankcase will create a flow of blow- .by from the crankcase through the hose 52, the fire and condensate trap 56, and the 'hose 5% to the portion of the air intake passage to which the hose St} is connected. The blowby is thereby mixed with the incoming air for combustion and returned to the combustion chambers of the engine to be consumed therein. The components of the system may be secured on or adjacent to the engine by any suitable bracket or fastening means which provide the aforedescribed vertical spacing relationships. The pressure differential existing between the tuning chamber 36 and the crankcase causes flow of blowby from the crankcase and reduces the pressure therein. The reduced pressure in the crankcase will cause the valve means in the filler cap to open to permit filtered air to flow into the crankcase. As the blowby passes through the baffle 62, oil entrained therein will be removed and returned to the crankcase. Condensate forming in the hose and tuning chamber 36 will be returned to the condensate trap. The copper mesh in the condensate trap provides a fire trap which prevents sparks or flames in the air induction passage means from reaching the crankcase.

Accordingly, it will be seen that a crankcase ventilating system which is simple in design, economical to manufacture, and easy to install has been provided. The ventilating system is readily adaptable for use with any of a plurality of engine designs and may 'be utilized on vehicles currently in use with a minimum of expense and repair, or may equally Well be installed as original equipment at the factory. Certain modifications in design and arrangement of the various parts have been presented. Such modifications and other alternative arrangements which utilize the principles disclosed herein are intended to be included within the scope of the invention as defined by the appended claims.

What is claimed is:

1. In a crankcase ventilating system for an internal combustion engine of conventional design including a crankcase, an oil filler tube communicating therewith, and a combustion air induction passage means communicating directly with the atmosphere for obtaining the combustion air for said engine; the invention comprising: filler tube cap means to permit flow of atmospheric ventilation air through said filler tube to said crankcase, filter means provided in said cap means to filter atmospheric ventilation air flowing tosaid crankcase, valve means provided in said cap means to limit flow to one direction fro the atmosphere to the crankcase and prevent reverse flow, ventilating passage means communicating with said crankcase at one end at a position spaced from the filler tube to establish a flow of ventilating air through the crankcase from the filler tube, and means connecting said ventilating passage means to said combustion air induction passage means at the other end whereby pressure difier entials existing between said combustion air induction passage means and said crankcase will cause a flow of ven-- tilation air and blowby from the crankcase to the combustion air induction passage means for mixing with the combustion air taken directly from the atmosphere.

2. The invention as defined in claim 1 and having condensate collecting means provided in said ventilating passage means to collect condensate removed from the blowby during passage through said ventilating passage means to said combustion air induction means, said ventilating passage means comprising lengths of flexible hose, one of said lengths of hose being connected at one end to said crankcase and at the other end to said condensate collecting means, said one end being located at a lower elevation connected at one end to said condensate collecting means 1 and communicating at the other end with said combusion air induction means, said one end being located at a lower elevation than said other end whereby condensate collecting in said other of said lengths of hose drains into said condensate collecting means, and valve means provided in said condensate collecting means to discharge condensate to the atmosphere and prevent flow of atmospheric air thereinto.

3. The invention as defined in claim 2 and wherein said condensate collecting means comprises a housing defining a central chamber, a baflie means dividing a portion of said central chamber, said one of said lengths of hose being connected to said housing and communicating with said chamber on one side of said baffle means, and said other of said lengths of hose being connected to and communicating with said chamber on the other side of said baflie means whereby flow of blowby directly between said lengths of hose is prevented.

4. The invention as defined in claim 3 and wherein fire trap means are provided in said chamber below said baflle means to prevent sparks or flames emanating from said combustion air induction passage means from passing through said condensate collecting'means to said crankcase.

5. The invention as defined in claim 2 and wherein said valve means comprises a condensate outlet passage 7 provided in the lower part of said housing and communicating with the atmosphere, a flap valve fixed to said housing adjacent said outlet passage and having a portion overlying and covering said outlet passage, said flap valve being movable outwardly in response to fluid pressure in said chamber to drain condensate to the atmosphere and being movable inwardly in response to atmospheric pressure when the pressure in said chamber is less than atmospheric pressure to prevent entry of atmospheric air.

6. The invention as defined in claim 2 and wherein oil removing means are provided in said one of said lengths of hose at a point vertically spaced above said one end thereof, and said oil removing means being effective to remove oil from said blowby whereby the oil drains back to the crankcase through said one of said lengths of hose.

7. A crankcase blowby ventilating system adapter kit arrangement for association with a conventional internal combustion engine having a crankcase, an oil filler tube, a replaceable filler tube cap, an air filter unit, a combustion air inlet formed in said air filter unit and communicating directly with the atmosphere, and combustion air induction passage means; the invention comprising: a re placeable fillertube cap, ventilating air inlet means provided in said cap and connecting said crankcase to the atmosphere through said filler tube, ventilating air flow control means provided in said cap, flexible hose means to connect and communicate said crankcase to said combustion air induction passage means, blowby-ventilating air inlet passage means formed separately from said combustion air inlet in a wall of said air filter unit at some pointcommunicating with said combustionair induction passage means therein, and said flexible hose means being inserted through the wall of said air filter unit and mounted in said inlet passage means so that pressure differentials existing between said combustion air induction passage means and said crankcase will establish a flow of blowby ventilating air through said'flexible hose means from said crankcase to said combustion air induction passage means.

8. The invention. as defined in claim 7 and wherein said blowby-ventilating air inlet passage means comprises an opening cut through saidside wall of said air filter unit 'at a point spaced from said combustionair inlet, said flexible hose means comprises a V-shaped circumferential groove means .adjacentthe ends thereof, said inlet passage in said wall of said air filter unit having a diameter substantially equal to or less than the diameter of the bottom of said V-shaped groove means whereby the end of said hose means may be c-ompressibly inserted into said inlet passage and secured therein by engagement of the wall of said air filter unit within said V-shaped groove when said hose means springs backto normal shape.

9. A crankcase ventilatingsystem adapter kit arrangement for association with a conventionalv internal combustion engine having a crankcase, an oil filler tube communicating with said crankcase, a cap for said oil filler tube, combustion air induction passage means, and an air cleaner unit including a 360 air inlet, a 360 filter unit, and a tuning chamber; the'invention comprising: a replacement cap for the conventional oil filler tube cap, said replacement cap having air inlet passage means to establish a flow of air to said crankcase through said oil filler tube, filtering means provided in said replacement cap, valve means provided in said replacement .cap to limit flow to a path from the atmosphere to the crankcase and prevent reverse flow from the crankcase to the atmosphere; an adapter tube means for connection to the engine and communication with the crankcase, means forming an inlet passage in the bottom wallot said tuning chamber, first flexible hose means connected at one end to said adapter tube means, a combination condensate and fire trap means, said first flexible hose means being connected at the other end to said combination condensate and fire trap at a point spaced below atleast some portions of said first flexible hose means, a second flexible hose means connected at one end to said inlet passage in the bottom wall of said tuning chamber and to said combination condensate trap and fire wall at the other end, said combination condensate and first trap being located below said inlet passage and below at least a portion of said first flexible hose means whereby condensate collecting in said tuning chamber'and said hose means drains to said combination condensate and fire trap, and means in said condensate and fire trap to dispose of condensate collecting therein.

10. A blowby ventilating system for an internal combustion engine having a carburetor, combustion air induction means associated with said carburetor and communicating directly with the atmosphere, and comprising: ventilating air inlet passage means connecting the interior of the engine to the atmosphere for ventilation, ventilating air-blowby outlet passage means separate from said inlet passage means and remotely spaced therefrom communicating with the interior of the engine, ventilating passage means connecting said outlet passage means and said combustion air induction means, engine vacuum means connected to said ventilating passage means to establish a flow of ventilating air from the atmosphere through the inlet passage means into and through the interior of the engine and to establish a mixed flow of ventilating air and blowby from the interior of the engine through the outlet passage means and the ventilating passage means to the combustion air induction means for mixing with combustion air flowing therethrough, and flow control valve means mounted in said inlet passage means.

11. A blowby ventilating system for an internal combustion engine having a carburetor, combustion air induction means associated with said carburetor and communicating directly with the atmosphere, and comprising: ventilating air inlet passage means connecting the interior of the engine to the atmosphere for ventilation, ventilating air-blowby outlet passage means separate from said inlet passage means and remotely spaced therefrom communicating with the interior of the engine, ventilating passage means connecting said outlet passage means and said combustion air induction means, engine vacuum means connected to said ventilating passage means to establish a flow of ventilating air from the atmosphere through the inlet passage means into and through the interior of the engine and to establish a mixed flow of ventilating air and blowby from the interior of the engine through the outlet passage means and the ventilating passage means to the combustion air induction means for mixing with combustion air flowing therethrough, a single flow control means mounted in said system, said flow control means being mounted in said air inlet passage means, and said flow control means being effective to control the rate of flow of ventilating air into the interior of the engine and to prevent reverse flow of blowby from the engine interior through said air inlet passage means to the atmosphere.

12. A blowby ventilating system for an internal combustion engine having a carburetor, combustion air induction means associated with said carburetor and connected directly to the atmosphere, a crankcase, an oil filler tube for said crankcase, a removable and replaceable filler tube cap mounted on said filler tube, the invention comprising: ventilating air inlet passage means connecting said crankcase to the atmosphere through said filler tube, said ventilating air inlet passage means including a portion formed in said filler tube cap, ventilating air-blowby outlet passage means communicating with the interior of the engine at a location remote from said filler tube, ventilating passage means connecting said outlet passage means and said combustion air induction means, means for connecting said ventilating passage means to the combustion air induction means, to establish a flow of ventilating air from the atmosphere through the inlet passage means into and through the interior of the engine and to establish a mixed flow of ventilating air and blowby from the interior of the engine through the outlet passage means and the ventilating passage means to the combustion air induction means, and flow control valve means mounted in said filler cap to control the rate of flow of ventilating air into the interior of the engine.

13. In an engine ventilating system for an internal combustion engine having a combustion air induction means communicating directly with the atmosphere, and comprising: a ventilating air inlet passage means for said engine, a blowby-ventilating air outlet passage means for said engine spaced and separate from said ventilating air inlet passage means to enable a flow of engine ventilating air to be established in said engine through said ventilating air passage means for mixing of ventilating air With blowby in said engine and for establishing a mixed flow of blowby and ventilating air from said engine, a blowbyventilating air passage means connecting said outlet passage means to said combustion air induction means to establish a mixed flow of blowby and ventilating air from the interior of said engine to said combustion air induction means by pressure differential existing therebetween, a single valve means mounted in said ventilating system between said ventilating air inlet passage means and said combustion air induction means, and said valve means being located in said ventilating air inlet passage means to control the rate of flow of ventilating air and preventing reverse flow of blowby to the atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 1,286,930 Buckner Dec. 10, 1918 1,427,337 Tracy Aug. 29, 1922 2,113,447 Hardinge Apr. 5, 1938 2,244,403 Root June 3, 1941 2,543,909 Hatheway Mar. 6, 1951 2,652,819 Nusbaum Sept. 22, 1953 2,742,057 Krieck Apr. 17, 1956 3,030,942 Thompson Apr. 24, 1962 UNITED STATES PATENT OFFICE CETIHCATE 0F CORRECTION Patent Noe 3,172,399 March 9, 1965 Ervin Co Lentz et al,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8, lines 1 and 2, for "replaceable" read replacement line 59, for "first" read fire Signed and sealed this 21st day of December 1965;

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. IN A CRANKCASE VENTILATING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE OF CONVENTIONAL DESIGN INCLUDING A CRANKCASE, AN OIL FILTER TUBE COMMUNICATING THEREWITH, AND A COMBUSTION AIR INDUCTION PASSAGE MEANS COMMUNICATING DIRECTLY WITH THE ATMOSPHERE FOR OBTAINING THE COMBUSTION AIR FOR SAID ENGINE; THE INVENTION COMPRISING: FILTER TUBE CAP MEANS TO PERMIT FLOW OF ATMOSPHERIC VENTILATION AIR THROUGH SAID FILLER TUBE TO SAID CRANKCASE, FILTER MEANS PROVIDED IN SAID CAP MEANS TO FILTER ATMOSPHEREIC VENTILATION AIR FLOWING TO SAID CRANKCASE, VALVE MEANS PROVIDED IN SAID CAP MEANS TO LIMIT FLOW TO ONE DIRECTION FROM THE ATMOSPHERE TO THE CRANKCASE AND PREVENT REVERSE FLOW, VENTILATING PASSAGE MEANS COMMUNICATING WITH SAID CRANKCASE AT ONE END AT A POSITION SPACED FROM THE FILLER TUBE TO ESTABLISH A FLOW OF VENTILATING AIR THROUGH THE CRANKCASE FROM THE FILLER TUBE, AND MEANS CONNECTING SAID VENTILATING PASSAGE MEANS TO SAID COMBUSTION AIR INDUCTION PASSAGE MEANS AT THE OTHER END WHEREBY PRESSURE DIFFERENTIALS EXISTING BETWEEN SAID COMBUSTION AIR INDUCTION PASSAGE MEANS AND SAID CRANKCASE WILL CAUSE A FLOW OF VENTILATION AIR AND BLOWBY FROM THE CRANKCASE TO THE COMBUSTION AIR INDUCTION PASSAGE MEANS FOR MIXING WITH THE COMBUSTION AIR TAKEN DIRECTLY FROM THE ATMOSPHERE. 